Shellfish and other marine life that attach to the bottoms of ships, marine structures, and various equipment and devices used in the ocean decrease the functionality of these structures over time. In an effort to address this problem, several types of paints have been suggested to prevent shellfish and other marine life attachment.
In the past, paint with organotin compounds such as tribytyltine were proposed and used to prevent shellfish attachment. However, marine contamination due to the organotin compounds has become problematic in recent years, and the use of such paints has been banned.
One composition of non-toxic antifouling coating is disclosed by U.S. Pat. No. 5,958,116. This composition is comprised of room temperature-cured silicone rubbers, silicone oil, and hydrophobic fumed silicon.
Other currently available technologies require expensive materials, and often do not yield satisfactory results. Japanese Published Unexamined Application Report Hei 11-349974 proposes algae-resistant/shellfish-resistant paint made by evenly mixing inorganic antimicrobial agents including silver and/or copper with water-repellant paint. Japanese Published Unexamined Application Report Hei 8-218004 proposes an anti-algae-and-shellfish-attachment paint that contains far-infrared ray radioactive ingredients such as ceramics, minus-ion radioactive materials like tourmaline, and garlic powder. Japanese Published Unexamined Application Report 2001-29818 suggests bio-fouling resistant paint made of conductive paint mixed with magnetic materials.